The present invention relates to material removal devices, and, more particularly, to an irrigation and aspiration instrument having a selectively hooked or straight portion at the operative end thereof for irrigating and aspirating material from relatively inaccessible places. Although by no means limited thereto, the present apparatus is of particular advantage when employed in surgical procedures for removing material from the capsular bag of the eye.
Conventional vibratory instruments for the removal of material from the eye have used a handpiece having a straight operative tip at the end thereof. U.S. Pat. No. 3,589,363, which is incorporated herein by reference, involves an instrument having a handpiece which has an elongated tip at one end. The elongated tip is inserted through an incision made in the cornea. The instrument is capable of vibrating the operative tip at ultrasonic frequencies of variable amplitude and duration to break apart particles of the material, such as a cataracted lens, to be removed.
A source of fluid and a source of fluid suction are provided at the operative end of the instrument, respectively, to dispense and withdraw fluid to and from the area in proximity of the material to be removed.
FIG. 1 illustrates the conventional solution to removing material from the eye. The opaque lens or cataract to be removed is designated as 10 and is encased in a membrane or capsular bag 12, including a front portion closest to the cornea, known as the anterior capsule 12a, and rear portion, known as the posterior capsule 12b.
Typically, a small incision 14 is made in the cornea 16 as far as possible from the center of the pupil area. The central portion of the anterior wall is opened up for access and instrument such as that described in U.S. Pat. No. 3,589,363 is used to fragment the cataracted lens and to aspirate the fragments from the accessible regions of the capsular bag such instrument has an elongated straight tip 20, seen in FIG. 1, capable of supporting ultrasonic vibrations. In this arrangement, particularly if the anterior wall opening is relatively small, only the central region of the interior of the capsular bag 12 is readily accessible to the tip, since the amount of manipulation by manually moving the handpiece 22 within the capsular bag 12 is relatively limited by the straight tip being confined at two locations along its length, namely, by the small incision in the cornea and also by the remaining peripheral portions of the anterior wall of the capsule.
For example, the handpiece 22 can be moved at angles A.sub.1, A.sub.2, A.sub.3 and A.sub.4 to enable the elongated straight tip 20 to reach different portions in the central region of the capsule. However, the capsule portions at the periphery of the capsular bag are not readily accessible to the elongated straight tip 20 because the size of the incision and the remaining anterior wall of the capsule 12 restrict the movement of the elongated straight tip 20. Therefore, the elongated tip 20 can not easily be moved to angles which would enable it to reach the interior peripheral portion of the capsule 12. Thus, it is very difficult for the surgeon using the conventional instrument to manipulate it so as to remove material, e.g. fragments of the cataracted lens, which is located at the inner peripheral regions of the anterior capsule 12.